/* Goxel 3D voxels editor
 *
 * copyright (c) 2015 Guillaume Chereau <guillaume@noctua-software.com>
 *
 * Goxel is free software: you can redistribute it and/or modify it under the
 * terms of the GNU General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later
 * version.

 * Goxel is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.

 * You should have received a copy of the GNU General Public License along with
 * goxel.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "goxel.h"

#include <stdarg.h>
#include <time.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <errno.h>

// Prevent warnings in stb code.
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
#ifdef WIN32
#pragma GCC diagnostic ignored "-Wmisleading-indentation"
#endif
#endif

#define STB_IMAGE_WRITE_IMPLEMENTATION
#define STB_IMAGE_IMPLEMENTATION
#define STBI_ONLY_PNG
#define STBI_ONLY_JPEG
#define STBI_ONLY_BMP
#include "stb_image.h"
#include "stb_image_write.h"

#if DEFINED(HAVE_LIBPNG)
#include <png.h>
#endif

#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif

#ifndef LOG_TIME
#   define LOG_TIME 1
#endif

static double get_log_time()
{
    static double origin = 0;
    double time;
    time = sys_get_time();
    if (!origin) origin = time;
    return time - origin;
}

void dolog(int level, const char *msg,
           const char *func, const char *file, int line, ...)
{
    const bool use_colors = !DEFINED(__APPLE__);
    char *msg_formatted, *full_msg;
    const char *format;
    char time_str[32] = "";
    va_list args;

    va_start(args, line);
    vasprintf(&msg_formatted, msg, args);
    va_end(args);

    if (use_colors && level >= GOX_LOG_WARN) {
        format = "\e[33;31m%s%-60s\e[m %s (%s:%d)";
    } else {
        format = "%s%-60s %s (%s:%d)";
    }

    if (DEFINED(LOG_TIME))
        sprintf(time_str, "%.3f: ", get_log_time());

    file = file + max(0, (int)strlen(file) - 20); // Truncate file path.
    asprintf(&full_msg, format, time_str, msg_formatted, func, file, line);
    sys_log(full_msg);

    free(msg_formatted);
    free(full_msg);
}

double get_unix_time(void)
{
    struct timeval tv;
    gettimeofday(&tv, NULL);
    return tv.tv_sec + tv.tv_usec / 1000.0 / 1000.0;
}

char *read_file(const char *path, int *size)
{
    FILE *file;
    char *ret = NULL;
    long read_size __attribute__((unused));
    int size_default;

    size = size ?: &size_default; // Allow to pass NULL as size;
    file = fopen(path, "rb");
    if (!file) return NULL;
    fseek(file, 0, SEEK_END);
    *size = (int)ftell(file);
    fseek(file, 0, SEEK_SET);
    ret = malloc(*size + 1);
    read_size = fread(ret, *size, 1, file);
    assert(read_size == 1 || *size == 0);
    ret[*size] = '\0';
    fclose(file);
    return ret;
}

uint8_t *img_read_from_mem(const char *data, int size,
                           int *w, int *h, int *bpp)
{
    assert(*bpp >= 0 && *bpp <= 4);
    return stbi_load_from_memory((uint8_t*)data, size, w, h, bpp, *bpp);
}

uint8_t *img_read(const char *path, int *width, int *height, int *bpp)
{
    int size;
    char *data;
    bool need_to_free = false;
    uint8_t *img;

    if (str_startswith(path, "asset://")) {
        data = (char*)assets_get(path, &size);
    } else {
        data = read_file(path, &size);
        need_to_free = true;
    }
    if (!data) LOG_E("Cannot open image %s", path);
    assert(data);
    img = img_read_from_mem(data, size, width, height, bpp);
    if (need_to_free) free(data);
    return img;
}

#if !DEFINED(HAVE_LIBPNG)

void img_write(const uint8_t *img, int w, int h, int bpp, const char *path)
{
    stbi_write_png(path, w, h, bpp, img, 0);
}

#else

void img_write(const uint8_t *img, int w, int h, int bpp, const char *path)
{
    int i;
    FILE *fp;
    png_structp png_ptr;
    png_infop info_ptr;

    fp = fopen(path, "wb");
    if (!fp) {
        LOG_E("Cannot open %s", path);
        return;
    }
    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
                                      NULL, NULL, NULL);
    info_ptr = png_create_info_struct(png_ptr);
    if (setjmp(png_jmpbuf(png_ptr))) {
       png_destroy_write_struct(&png_ptr, &info_ptr);
       fclose(fp);
       return;
    }
    png_init_io(png_ptr, fp);
    png_set_IHDR(png_ptr, info_ptr, w, h, 8,
                 bpp == 3 ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA,
                 PNG_INTERLACE_NONE,
                 PNG_COMPRESSION_TYPE_DEFAULT,
                 PNG_FILTER_TYPE_DEFAULT);

    png_write_info(png_ptr, info_ptr);
    for (i = 0; i < h; i++)
        png_write_row(png_ptr, (png_bytep)(img + i * w * bpp));
    png_write_end(png_ptr, info_ptr);
    png_destroy_write_struct(&png_ptr, &info_ptr);
    fclose(fp);
}

#endif

uint8_t *img_write_to_mem(const uint8_t *img, int w, int h, int bpp, int *size)
{
    return stbi_write_png_to_mem((void*)img, 0, w, h, bpp, size);
}

bool str_endswith(const char *str, const char *end)
{
    if (!str || !end) return false;
    if (strlen(str) < strlen(end)) return false;
    const char *start = str + strlen(str) - strlen(end);
    return strcmp(start, end) == 0;
}

bool str_startswith(const char *s1, const char *s2)
{
    if (!s1 || !s2) return false;
    if (strlen(s1) < strlen(s2)) return false;
    return strncmp(s1, s2, strlen(s2)) == 0;
}

void img_downsample(const uint8_t *img, int w, int h, int bpp,
                    uint8_t *out)
{
#define IX(x, y, k) ((((size_t)y) * w + (x)) * bpp + (k))
    int i, j, k;

    assert(w % 2 == 0 && h % 2 == 0);

    for (i = 0; i < h; i += 2)
    for (j = 0; j < w; j += 2)
    for (k = 0; k < bpp; k++) {
        out[(i * w / 4 + j / 2) * bpp + k] = (
                            img[IX(j + 0, i + 0, k)] +
                            img[IX(j + 0, i + 1, k)] +
                            img[IX(j + 1, i + 0, k)] +
                            img[IX(j + 1, i + 1, k)]) / 4;
    }
#undef IX
}

// Like gluUnproject.
void unproject(const float win[3], const float model[4][4],
               const float proj[4][4], const float viewport[4],
               float out[3])
{
    float inv[4][4];
    float p[4];

    mat4_mul(proj, model, inv);
    mat4_invert(inv, inv);
    vec4_set(p, (win[0] - viewport[0]) / viewport[2] * 2 - 1,
                (win[1] - viewport[1]) / viewport[3] * 2 - 1,
                2 * win[2] - 1, 1);
    mat4_mul_vec4(inv, p, p);
    if (p[3]) vec3_imul(p, 1 / p[3]);
    vec3_copy(p, out);
}

int unix_to_dtf(double t, int *iy, int *im, int *id, int *h, int *m, int *s)
{
    time_t time = (int)t;
    struct tm *tm;
    tm = localtime(&time);
    if (!tm) return -1;
    *iy = tm->tm_year + 1900;
    *im = tm->tm_mon + 1;
    *id = tm->tm_mday;
    *h = tm->tm_hour;
    *m = tm->tm_min;
    *s = tm->tm_sec;
    return 0;
}

// From blender source code.
int utf_16_to_8(const wchar_t *in16, char *out8, size_t size8)
{
    char *out8end = out8 + size8;
    wchar_t u = 0;
    int err = 0;
    if (!size8 || !in16 || !out8) return -1;
    out8end--;

    for (; out8 < out8end && (u = *in16); in16++, out8++) {
        if (u < 0x0080) {
            *out8 = u;
        }
        else if (u < 0x0800) {
            if (out8 + 1 >= out8end) break;
            *out8++ = (0x3 << 6) | (0x1F & (u >> 6));
            *out8  = (0x1 << 7) | (0x3F & (u));
        }
        else if (u < 0xD800 || u >= 0xE000) {
            if (out8 + 2 >= out8end) break;
            *out8++ = (0x7 << 5) | (0xF & (u >> 12));
            *out8++ = (0x1 << 7) | (0x3F & (u >> 6));
            *out8  = (0x1 << 7) | (0x3F & (u));
        }
        else if (u < 0xDC00) {
            wchar_t u2 = *++in16;

            if (!u2) break;
            if (u2 >= 0xDC00 && u2 < 0xE000) {
                if (out8 + 3 >= out8end) break; else {
                    unsigned int uc = 0x10000 + (u2 - 0xDC00) + ((u - 0xD800) << 10);

                    *out8++ = (0xF << 4) | (0x7 & (uc >> 18));
                    *out8++ = (0x1 << 7) | (0x3F & (uc >> 12));
                    *out8++ = (0x1 << 7) | (0x3F & (uc >> 6));
                    *out8  = (0x1 << 7) | (0x3F & (uc));
                }
            }
            else {
                out8--; err = -1;
            }
        }
        else if (u < 0xE000) {
            out8--; err = -1;
        }
    }
    *out8 = *out8end = 0;
    if (*in16) err = -1;
    return err;
}


/* Function: b64_decode
 * Decode a base64 string
 *
 * Parameters:
 *   src  - A base 64 encoded string.
 *   dest - Buffer that will receive the decoded value or NULL.  If set to
 *          NULL the function just returns the size of the decoded data.
 *
 * Return:
 *   The size of the decoded data.
 */
int b64_decode(const char *src, void *dest)
{
    const char TABLE[] =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    int len = strlen(src);
    uint8_t *p = dest;
    #define b64_value(c) ((strchr(TABLE, c) ?: TABLE) - TABLE)
    #define isbase64(c) (c && strchr(TABLE, c))

    if (*src == 0) return 0;
    if (!p) return ((len + 3) / 4) * 3;
    do {
        char a = b64_value(src[0]);
        char b = b64_value(src[1]);
        char c = b64_value(src[2]);
        char d = b64_value(src[3]);
        *p++ = (a << 2) | (b >> 4);
        *p++ = (b << 4) | (c >> 2);
        *p++ = (c << 6) | d;
        if (!isbase64(src[1])) {
            p -= 2;
            break;
        }
        else if (!isbase64(src[2])) {
            p -= 2;
            break;
        }
        else if (!isbase64(src[3])) {
            p--;
            break;
        }
        src += 4;
        while (*src && (*src == 13 || *src == 10)) src++;
    } while (len -= 4);
    return p - (uint8_t*)dest;
}

// Table taken from redis sources.
static const uint64_t crc64_tab[256] = {
    UINT64_C(0x0000000000000000), UINT64_C(0x7ad870c830358979),
    UINT64_C(0xf5b0e190606b12f2), UINT64_C(0x8f689158505e9b8b),
    UINT64_C(0xc038e5739841b68f), UINT64_C(0xbae095bba8743ff6),
    UINT64_C(0x358804e3f82aa47d), UINT64_C(0x4f50742bc81f2d04),
    UINT64_C(0xab28ecb46814fe75), UINT64_C(0xd1f09c7c5821770c),
    UINT64_C(0x5e980d24087fec87), UINT64_C(0x24407dec384a65fe),
    UINT64_C(0x6b1009c7f05548fa), UINT64_C(0x11c8790fc060c183),
    UINT64_C(0x9ea0e857903e5a08), UINT64_C(0xe478989fa00bd371),
    UINT64_C(0x7d08ff3b88be6f81), UINT64_C(0x07d08ff3b88be6f8),
    UINT64_C(0x88b81eabe8d57d73), UINT64_C(0xf2606e63d8e0f40a),
    UINT64_C(0xbd301a4810ffd90e), UINT64_C(0xc7e86a8020ca5077),
    UINT64_C(0x4880fbd87094cbfc), UINT64_C(0x32588b1040a14285),
    UINT64_C(0xd620138fe0aa91f4), UINT64_C(0xacf86347d09f188d),
    UINT64_C(0x2390f21f80c18306), UINT64_C(0x594882d7b0f40a7f),
    UINT64_C(0x1618f6fc78eb277b), UINT64_C(0x6cc0863448deae02),
    UINT64_C(0xe3a8176c18803589), UINT64_C(0x997067a428b5bcf0),
    UINT64_C(0xfa11fe77117cdf02), UINT64_C(0x80c98ebf2149567b),
    UINT64_C(0x0fa11fe77117cdf0), UINT64_C(0x75796f2f41224489),
    UINT64_C(0x3a291b04893d698d), UINT64_C(0x40f16bccb908e0f4),
    UINT64_C(0xcf99fa94e9567b7f), UINT64_C(0xb5418a5cd963f206),
    UINT64_C(0x513912c379682177), UINT64_C(0x2be1620b495da80e),
    UINT64_C(0xa489f35319033385), UINT64_C(0xde51839b2936bafc),
    UINT64_C(0x9101f7b0e12997f8), UINT64_C(0xebd98778d11c1e81),
    UINT64_C(0x64b116208142850a), UINT64_C(0x1e6966e8b1770c73),
    UINT64_C(0x8719014c99c2b083), UINT64_C(0xfdc17184a9f739fa),
    UINT64_C(0x72a9e0dcf9a9a271), UINT64_C(0x08719014c99c2b08),
    UINT64_C(0x4721e43f0183060c), UINT64_C(0x3df994f731b68f75),
    UINT64_C(0xb29105af61e814fe), UINT64_C(0xc849756751dd9d87),
    UINT64_C(0x2c31edf8f1d64ef6), UINT64_C(0x56e99d30c1e3c78f),
    UINT64_C(0xd9810c6891bd5c04), UINT64_C(0xa3597ca0a188d57d),
    UINT64_C(0xec09088b6997f879), UINT64_C(0x96d1784359a27100),
    UINT64_C(0x19b9e91b09fcea8b), UINT64_C(0x636199d339c963f2),
    UINT64_C(0xdf7adabd7a6e2d6f), UINT64_C(0xa5a2aa754a5ba416),
    UINT64_C(0x2aca3b2d1a053f9d), UINT64_C(0x50124be52a30b6e4),
    UINT64_C(0x1f423fcee22f9be0), UINT64_C(0x659a4f06d21a1299),
    UINT64_C(0xeaf2de5e82448912), UINT64_C(0x902aae96b271006b),
    UINT64_C(0x74523609127ad31a), UINT64_C(0x0e8a46c1224f5a63),
    UINT64_C(0x81e2d7997211c1e8), UINT64_C(0xfb3aa75142244891),
    UINT64_C(0xb46ad37a8a3b6595), UINT64_C(0xceb2a3b2ba0eecec),
    UINT64_C(0x41da32eaea507767), UINT64_C(0x3b024222da65fe1e),
    UINT64_C(0xa2722586f2d042ee), UINT64_C(0xd8aa554ec2e5cb97),
    UINT64_C(0x57c2c41692bb501c), UINT64_C(0x2d1ab4dea28ed965),
    UINT64_C(0x624ac0f56a91f461), UINT64_C(0x1892b03d5aa47d18),
    UINT64_C(0x97fa21650afae693), UINT64_C(0xed2251ad3acf6fea),
    UINT64_C(0x095ac9329ac4bc9b), UINT64_C(0x7382b9faaaf135e2),
    UINT64_C(0xfcea28a2faafae69), UINT64_C(0x8632586aca9a2710),
    UINT64_C(0xc9622c4102850a14), UINT64_C(0xb3ba5c8932b0836d),
    UINT64_C(0x3cd2cdd162ee18e6), UINT64_C(0x460abd1952db919f),
    UINT64_C(0x256b24ca6b12f26d), UINT64_C(0x5fb354025b277b14),
    UINT64_C(0xd0dbc55a0b79e09f), UINT64_C(0xaa03b5923b4c69e6),
    UINT64_C(0xe553c1b9f35344e2), UINT64_C(0x9f8bb171c366cd9b),
    UINT64_C(0x10e3202993385610), UINT64_C(0x6a3b50e1a30ddf69),
    UINT64_C(0x8e43c87e03060c18), UINT64_C(0xf49bb8b633338561),
    UINT64_C(0x7bf329ee636d1eea), UINT64_C(0x012b592653589793),
    UINT64_C(0x4e7b2d0d9b47ba97), UINT64_C(0x34a35dc5ab7233ee),
    UINT64_C(0xbbcbcc9dfb2ca865), UINT64_C(0xc113bc55cb19211c),
    UINT64_C(0x5863dbf1e3ac9dec), UINT64_C(0x22bbab39d3991495),
    UINT64_C(0xadd33a6183c78f1e), UINT64_C(0xd70b4aa9b3f20667),
    UINT64_C(0x985b3e827bed2b63), UINT64_C(0xe2834e4a4bd8a21a),
    UINT64_C(0x6debdf121b863991), UINT64_C(0x1733afda2bb3b0e8),
    UINT64_C(0xf34b37458bb86399), UINT64_C(0x8993478dbb8deae0),
    UINT64_C(0x06fbd6d5ebd3716b), UINT64_C(0x7c23a61ddbe6f812),
    UINT64_C(0x3373d23613f9d516), UINT64_C(0x49aba2fe23cc5c6f),
    UINT64_C(0xc6c333a67392c7e4), UINT64_C(0xbc1b436e43a74e9d),
    UINT64_C(0x95ac9329ac4bc9b5), UINT64_C(0xef74e3e19c7e40cc),
    UINT64_C(0x601c72b9cc20db47), UINT64_C(0x1ac40271fc15523e),
    UINT64_C(0x5594765a340a7f3a), UINT64_C(0x2f4c0692043ff643),
    UINT64_C(0xa02497ca54616dc8), UINT64_C(0xdafce7026454e4b1),
    UINT64_C(0x3e847f9dc45f37c0), UINT64_C(0x445c0f55f46abeb9),
    UINT64_C(0xcb349e0da4342532), UINT64_C(0xb1eceec59401ac4b),
    UINT64_C(0xfebc9aee5c1e814f), UINT64_C(0x8464ea266c2b0836),
    UINT64_C(0x0b0c7b7e3c7593bd), UINT64_C(0x71d40bb60c401ac4),
    UINT64_C(0xe8a46c1224f5a634), UINT64_C(0x927c1cda14c02f4d),
    UINT64_C(0x1d148d82449eb4c6), UINT64_C(0x67ccfd4a74ab3dbf),
    UINT64_C(0x289c8961bcb410bb), UINT64_C(0x5244f9a98c8199c2),
    UINT64_C(0xdd2c68f1dcdf0249), UINT64_C(0xa7f41839ecea8b30),
    UINT64_C(0x438c80a64ce15841), UINT64_C(0x3954f06e7cd4d138),
    UINT64_C(0xb63c61362c8a4ab3), UINT64_C(0xcce411fe1cbfc3ca),
    UINT64_C(0x83b465d5d4a0eece), UINT64_C(0xf96c151de49567b7),
    UINT64_C(0x76048445b4cbfc3c), UINT64_C(0x0cdcf48d84fe7545),
    UINT64_C(0x6fbd6d5ebd3716b7), UINT64_C(0x15651d968d029fce),
    UINT64_C(0x9a0d8ccedd5c0445), UINT64_C(0xe0d5fc06ed698d3c),
    UINT64_C(0xaf85882d2576a038), UINT64_C(0xd55df8e515432941),
    UINT64_C(0x5a3569bd451db2ca), UINT64_C(0x20ed197575283bb3),
    UINT64_C(0xc49581ead523e8c2), UINT64_C(0xbe4df122e51661bb),
    UINT64_C(0x3125607ab548fa30), UINT64_C(0x4bfd10b2857d7349),
    UINT64_C(0x04ad64994d625e4d), UINT64_C(0x7e7514517d57d734),
    UINT64_C(0xf11d85092d094cbf), UINT64_C(0x8bc5f5c11d3cc5c6),
    UINT64_C(0x12b5926535897936), UINT64_C(0x686de2ad05bcf04f),
    UINT64_C(0xe70573f555e26bc4), UINT64_C(0x9ddd033d65d7e2bd),
    UINT64_C(0xd28d7716adc8cfb9), UINT64_C(0xa85507de9dfd46c0),
    UINT64_C(0x273d9686cda3dd4b), UINT64_C(0x5de5e64efd965432),
    UINT64_C(0xb99d7ed15d9d8743), UINT64_C(0xc3450e196da80e3a),
    UINT64_C(0x4c2d9f413df695b1), UINT64_C(0x36f5ef890dc31cc8),
    UINT64_C(0x79a59ba2c5dc31cc), UINT64_C(0x037deb6af5e9b8b5),
    UINT64_C(0x8c157a32a5b7233e), UINT64_C(0xf6cd0afa9582aa47),
    UINT64_C(0x4ad64994d625e4da), UINT64_C(0x300e395ce6106da3),
    UINT64_C(0xbf66a804b64ef628), UINT64_C(0xc5bed8cc867b7f51),
    UINT64_C(0x8aeeace74e645255), UINT64_C(0xf036dc2f7e51db2c),
    UINT64_C(0x7f5e4d772e0f40a7), UINT64_C(0x05863dbf1e3ac9de),
    UINT64_C(0xe1fea520be311aaf), UINT64_C(0x9b26d5e88e0493d6),
    UINT64_C(0x144e44b0de5a085d), UINT64_C(0x6e963478ee6f8124),
    UINT64_C(0x21c640532670ac20), UINT64_C(0x5b1e309b16452559),
    UINT64_C(0xd476a1c3461bbed2), UINT64_C(0xaeaed10b762e37ab),
    UINT64_C(0x37deb6af5e9b8b5b), UINT64_C(0x4d06c6676eae0222),
    UINT64_C(0xc26e573f3ef099a9), UINT64_C(0xb8b627f70ec510d0),
    UINT64_C(0xf7e653dcc6da3dd4), UINT64_C(0x8d3e2314f6efb4ad),
    UINT64_C(0x0256b24ca6b12f26), UINT64_C(0x788ec2849684a65f),
    UINT64_C(0x9cf65a1b368f752e), UINT64_C(0xe62e2ad306bafc57),
    UINT64_C(0x6946bb8b56e467dc), UINT64_C(0x139ecb4366d1eea5),
    UINT64_C(0x5ccebf68aecec3a1), UINT64_C(0x2616cfa09efb4ad8),
    UINT64_C(0xa97e5ef8cea5d153), UINT64_C(0xd3a62e30fe90582a),
    UINT64_C(0xb0c7b7e3c7593bd8), UINT64_C(0xca1fc72bf76cb2a1),
    UINT64_C(0x45775673a732292a), UINT64_C(0x3faf26bb9707a053),
    UINT64_C(0x70ff52905f188d57), UINT64_C(0x0a2722586f2d042e),
    UINT64_C(0x854fb3003f739fa5), UINT64_C(0xff97c3c80f4616dc),
    UINT64_C(0x1bef5b57af4dc5ad), UINT64_C(0x61372b9f9f784cd4),
    UINT64_C(0xee5fbac7cf26d75f), UINT64_C(0x9487ca0fff135e26),
    UINT64_C(0xdbd7be24370c7322), UINT64_C(0xa10fceec0739fa5b),
    UINT64_C(0x2e675fb4576761d0), UINT64_C(0x54bf2f7c6752e8a9),
    UINT64_C(0xcdcf48d84fe75459), UINT64_C(0xb71738107fd2dd20),
    UINT64_C(0x387fa9482f8c46ab), UINT64_C(0x42a7d9801fb9cfd2),
    UINT64_C(0x0df7adabd7a6e2d6), UINT64_C(0x772fdd63e7936baf),
    UINT64_C(0xf8474c3bb7cdf024), UINT64_C(0x829f3cf387f8795d),
    UINT64_C(0x66e7a46c27f3aa2c), UINT64_C(0x1c3fd4a417c62355),
    UINT64_C(0x935745fc4798b8de), UINT64_C(0xe98f353477ad31a7),
    UINT64_C(0xa6df411fbfb21ca3), UINT64_C(0xdc0731d78f8795da),
    UINT64_C(0x536fa08fdfd90e51), UINT64_C(0x29b7d047efec8728),
};

/*
 * Function: crc64
 * Compute crc64 hash
 *
 * Parameters:
 *   crc    - Initial crc value.
 *   s      - Data pointer.
 *   len    - Data size.
 *
 * Return:
 *   The new crc64 value.
 */
uint64_t crc64(uint64_t crc, const uint8_t *s, uint64_t len)
{
    uint64_t j, byte;
    for (j = 0; j < len; j++) {
        byte = s[j];
        crc = crc64_tab[(uint8_t)crc ^ byte] ^ (crc >> 8);
    }
    return crc;
}
